Crystal structure of mammalian poly(A) polymerase in complex with an analog of ATP.Martin, G., Keller, W., Doublie, S.
(2000) EMBO J. 19: 4193-4203
- PubMed: 10944102
- DOI: 10.1093/emboj/19.16.4193
- PubMed Abstract:
- Mapping of ATP binding regions in poly(A) polymerases by photoaffinity labeling and by mutational analysis identifies a domain conserved in many nucleotidyltransferases.
Martin, G.,Jeno, P.,Keller, W.
(1999) Protein Sci. 8: 2380
- Mutational analysis of mammalian poly(A) polymerase identifies a region for primer binding and catalytic domain, homologous to the family X polymerases, and to other nucleotidyltransferases.
Martin, G.,Keller, W.
(1996) Embo J. 15: 2593
In eukaryotes, polyadenylation of pre-mRNA plays an essential role in the initiation step of protein synthesis, as well as in the export and stability of mRNAs. Poly(A) polymerase, the enzyme at the heart of the polyadenylation machinery, is a templa ...
In eukaryotes, polyadenylation of pre-mRNA plays an essential role in the initiation step of protein synthesis, as well as in the export and stability of mRNAs. Poly(A) polymerase, the enzyme at the heart of the polyadenylation machinery, is a template-independent RNA polymerase which specifically incorporates ATP at the 3' end of mRNA. We have solved the crystal structure of bovine poly(A) polymerase bound to an ATP analog at 2.5 A resolution. The structure revealed expected and unexpected similarities to other proteins. As expected, the catalytic domain of poly(A) polymerase shares substantial structural homology with other nucleotidyl transferases such as DNA polymerase beta and kanamycin transferase. The C-terminal domain unexpectedly folds into a compact domain reminiscent of the RNA-recognition motif fold. The three invariant aspartates of the catalytic triad ligate two of the three active site metals. One of these metals also contacts the adenine ring. Furthermore, conserved, catalytically important residues contact the nucleotide. These contacts, taken together with metal coordination of the adenine base, provide a structural basis for ATP selection by poly(A) polymerase.
Department of Cell Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.